Description of problem:
Cal shows incorrect week number, when week starts on Sunday. 
Cal utility is one week behind, which is also shown in GUI settings.
When using Monday as first day of the week, cal shows correct week numbers.

Version-Release number of selected component (if applicable):
util-linux-2.26.2-1.fc22.x86_64
util-linux-2.24.2-2.fc20.x86_64


How reproducible:
Always

Steps to Reproduce:
Compare 
$ cal -w 
$ cal -w -m


Actual results:
In the first case, current week is 31 (incorrect)
      August 2015      
   Su Mo Tu We Th Fr Sa
30                    1 
31  2  3  4  5  6  7  8 
32  9 10 11 12 13 14 15 
33 16 17 18 19 20 21 22 
34 23 24 25 26 27 28 29 
35 30 31 

Expected results:
In the second case, current week is 32 (correct)
      August 2015      
   Mo Tu We Th Fr Sa Su
31                 1  2 
32  3  4  5  6  7  8  9 
33 10 11 12 13 14 15 16 
34 17 18 19 20 21 22 23 
35 24 25 26 27 28 29 30 
36 31

Additional info: